System for magnetic resonance imaging assisted surgery

ABSTRACT

A system and method for magnetic resonance imaging assisted surgery. The system includes an antenna support assembly and an antenna that are used to acquire real time images of the surgical site that may be used by a surgeon to more accurately perform the surgical procedure. The method comprises acquiring real time images of the surgical site and feeding back the images to a surgeon performing the surgical procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.11/276,700, filed on Mar. 21, 2007, which claims the benefit of thefiling date of U.S. Provisional Patent Application No. 60/784,151 filedMar. 21, 2006, the disclosures of which are hereby incorporated hereinby reference.

BACKGROUND OF THE INVENTION

The present patent application relates to magnetic resonance imagingapparatus and methods for using such apparatus in surgical procedures.

In magnetic resonance imaging, an object to be imaged as, for example, abody of a human subject is exposed to a strong, substantially constantstatic magnetic field. The static magnetic field causes the spin vectorsof certain atomic nuclei within the body to randomly rotate or “precess”around an axis parallel to the direction of the static magnetic field.Radio frequency excitation energy is applied to the body, and thisenergy causes the nuclei to “precess” in phase and in an excited state.As the precessing atomic nuclei relax, weak radio frequency signals areemitted; such radio frequency signals are referred to herein as magneticresonance signals.

Different tissues produce different signal characteristics. Furthermore,relaxation times are the dominant factor in determining signal strength.In addition, tissues having a high density of certain nuclei willproduce stronger signals than tissues with a low density of such nuclei.Relatively small gradients in the magnetic field are superimposed on thestatic magnetic field at various times during the process so thatmagnetic resonance signals from different portions of the patient's bodydiffer in phase and/or frequency. If the process is repeated numeroustimes using different combinations of gradients, the signals from thevarious repetitions together provide enough information to form a map ofsignal characteristics versus location within the body. Such a map canbe reconstructed by conventional techniques well known in the magneticresonance imaging art, and can be displayed as a pictorial image of thetissues as known in the art.

The magnetic resonance imaging technique offers numerous advantages overother imaging techniques. MRI does not expose either the patient ormedical personnel to X-rays and offers important safety advantages.Also, magnetic resonance imaging can obtain images of soft tissues andother features within the body which are not readily visualized usingother imaging techniques. Accordingly, magnetic resonance imaging hasbeen widely adopted in the medical and allied arts.

Many conventional magnetic resonance imaging instruments require that apatient lie on a horizontal bed that is then advanced into a tubularbore within a super-conducting solenoidal magnet used to generate thestatic magnetic field. These units force the patient to undergo anintensely claustrophobic experience while being imaged. Other forms ofmagnetic resonance imaging apparatus, commonly referred to as “open MRIapparatus,” were developed to provide a less claustrophobic experienceto the patient and greater access to the patient by medical personnelduring the imaging procedure. However, even in this improved apparatus,the patient was still positioned inside the apparatus, and medicalpersonnel attending to the patient would reach into the apparatus fromoutside, so that components of the apparatus still obstructed access tosome extent.

As described in U.S. Pat. Nos. 6,335,623 and 6,541,973, which areassigned to the assignee of the present application, the disclosures ofwhich are hereby incorporated by reference herein, this problem can besolved completely by providing space within the apparatus itself toaccommodate medical personnel in addition to the patient. Thus, as shownin certain embodiments disclosed in the '973 and '623 patents, themagnet may include a ferromagnetic frame incorporating a floor, aceiling and a pair of side walls extending between the floor and theceiling, a lower ferromagnetic pole structure projecting upwardly fromthe floor and an upper ferromagnetic pole structure projectingdownwardly from the ceiling. The projecting pole structures define apatient-receiving space between them. The magnet also includes fluxgenerating elements such as resistive or superconducting coils orpermanent magnets arranged to direct flux through the frame so that theflux passes through the patient-receiving space between the polestructures and returns through the side walls, floor and ceiling. Thespace between the side walls may be of essentially any size, but isdesirably sufficient so that medical personnel can enter into the spacealong with the patient. In effect, the frame preferably forms a roomwith a pole structure projecting down from the ceiling and another polestructure projecting up from the floor. The medical personnel inside theroom have essentially unobstructed access to the patient from any side.It is, thus, quite practical to perform surgery or other medicalprocedure on a patient while the patient is in the patient-receivingspace of the MRI apparatus. The room defined by the magnet frame may beequipped with features normally found in operating rooms, so that themagnet effectively becomes an MRI-capable operating room. Thus, surgeryor other procedures can be performed under MRI guidance.

As shown in detail in the '973 patent, a patient positioning device mayinclude a chassis having a pair of vertically extending end portions orleg portions and a bridge portion extending between these leg portions.The end portions of the chassis are spaced apart by a distance greaterthan the dimension of the lower pole structure. A bed is movably mountedto the chassis so that the bed can move and pivot in various directionsrelative to the chassis. The chassis is provided with wheels so that thepatient can be positioned in the patient-receiving space of the magnetby placing the patient on the bed and wheeling the chassis intoposition, with the end portions of chassis disposed on opposite sides ofthe lower pole structure and with the bridge portion of the chassisspanning across the lower pole structure, so that the bridge portion ofthe chassis and the bed lie within the patient-receiving space. Thepatient can then be repositioned in various ways as by turning the bedabout a vertical axis, tilting the bed about a horizontal axis orsliding the bed relative to the chassis. These arrangements provideextraordinary versatility in imaging of the patient and in positioningthe patient for medical procedures.

However, further improvement would be desirable. For example, it isdesirable to have a magnetic resonance image of the portion of thepatient's anatomy on which surgery is being performed. Typically, MRIassisted surgical procedures comprise scanning the patient's anatomy ofinterest beforehand. The scans are then referred to during surgery or insome instances the scans are used to build models. The models are thenused by a surgeon in planning the actual surgery or in a preoperativesimulation of the surgery. Additional preoperative uses of these imagesinclude localization of the surgical site and blood vessel andanatomical relationships. Although these techniques enhance the surgicalprocedure, they do not provide a surgeon with a real time view of thesurgical site so as to provide direct visual feedback to the surgeon.

The present invention addresses the foregoing needs.

SUMMARY OF THE INVENTION

In one aspect the present invention comprises a system for magneticresonance imaging assisted surgery. The system preferably comprises amagnet having a lower pole and an upper pole arranged along a verticalaxis defining a patient receiving space therebetween; a bed positionedwithin the patient receiving space for supporting a patient, the bedhaving a frame and a support surface onto which the patient ispositioned; and an antenna support assembly mounted to the bed, thesupport assembly being adapted to support a housing having one or moreantenna coils, the housing comprising a skeletal structure that allowsaccess to the portion of patient's anatomy adjacent the housing and fromwhich signals are received by the coils.

In another aspect, the present invention may comprise a method forperforming a surgical procedure. The method preferably comprisespositioning a patient on bed in a receiving space of a magneticresonance imaging magnet; positioning an antenna coil assembly adjacentto a portion of the patient's anatomy; acquiring a magnetic resonanceimage of the patient's anatomy adjacent the antenna coil assembly;performing a surgical procedure on the patient's anatomy adjacent theantenna coil assembly; and repetitively acquiring images of thepatient's anatomy adjacent the antenna coil assembly as the surgicalprocedure is performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a magnetic resonance imaging system inaccordance with an aspect of the present invention.

FIG. 2 is a perspective view of a magnetic resonance system inaccordance with an aspect of the present invention.

FIG. 3 is perspective view of a magnetic resonance imaging system inaccordance with an aspect of the present invention.

FIG. 4 is a perspective view of an antenna support assembly inaccordance with an aspect of the present invention.

FIG. 5A shows a housing of a planar quad coil assembly with a section ofthe housing removed to reveal the coil geometry.

FIG. 5B shows a housing of a planar ring coil assembly.

FIG. 5C shows a housing of a double-planar shoulder coil assembly.

FIG. 6A shows several views of an antenna support assembly in accordancewith an aspect of the present invention.

FIG. 6B shows several views of a bed locking sub-assembly in accordancewith an aspect of the present invention.

FIG. 6C shows several views of a coil locking sub-assembly in accordancewith an aspect of the present invention.

FIGS. 7A and 7B show respective front and rear views of an antenna andbed assembly in accordance with an aspect of the present invention.

FIG. 8 shows a cross section detail of the bed extrusion.

DETAILED DESCRIPTION

Turning now to FIG. 1, there is shown a magnetic resonance imagingsystem 100 in accordance with an aspect of the present invention. Thesystem 100 includes a magnet (while not shown in full, components of themagnet are shown and identified subsequently) and a patient supportapparatus 110. The magnet includes a lower magnet pole structure 112that projects upwardly from a floor 116. As is discussed in greaterdetail in U.S. application Ser. No. 11/236,184, the disclosure of whichis incorporated herein by reference, the floor 116 is a false floor thatis supported above a well floor and is isolated from the magnet. Themagnet also includes an upper magnet pole structure 120 that projectsdownwardly from a ceiling 122. For clarity, the upper magnet polestructure 120 is shown schematically in broken lines projectingdownwardly through a portion of the ceiling 122. Other structuresassociated with the magnet are located beneath floor 116, above theceiling 122, and behind the side walls 123, but are not shown forclarity. In addition, a front wall (not shown) is also used to house thesystem in a room, which may serve as an operating theater. The lower andupper pole structures 112, 120 are aligned with each other along a polaraxis 124 that generally extends vertically in the y-direction. The upperand lower pole structures 112, 120 are spaced apart so as to define apatient receiving space 128 therebetween. As shown in FIG. 1, a patientP may be positioned within the receiving space 128 using the patientsupport system 110. Other personnel may then access the patient P whilein patient receiving space 128. These personnel may include doctors,nurses, technicians or an entire surgical team. Advantageously, thesystem 100 is housed in a room that forms an operating theater.

As shown in FIG. 1, the lower pole structure 112 is surrounded by ashroud 130 that is equipped to receive the patient support apparatus 110that is also included with the system 100. The shroud 130 is equippedwith a rotatable frame 136 that includes ledges 140 onto which thepatient support apparatus 110 may be docked and mounted. When thepatient support apparatus 110 is mounted to the frame 136 it may berotated about the polar axis 124. In addition, the patient supportapparatus 110 includes a frame 138 onto which a bed or slab 142 isslidably mounted such that slab 142 is allowed to cantilever relative tothe magnet pole. As such, either end of patient support apparatus 110may project outward from the magnet pole and be rotated. This allows anyportion of the patient's anatomy to be located in the imaging volumeand/or iso-center of the magnet, i.e., within the center of the imagingvolume.

The system 100 further includes a pair of safety gates 150 that arelocated at the front 154 of the magnet. Each gate 150 is connected to arail 156, which is mounted to the floor 116. A lift platform 160 formspart of an elevator system, which is located towards the front 154 ofthe magnet. The rails 156 are equipped with a light gate sensor system164 that detects the presence or absence of an object, e.g., medicalpersonnel or bed 142, that may be supported by the platform 160. Thelight gate system 164 works in conjunction with an elevator system toautomatically raise the lift platform 160 under certain conditions. Inparticular, if the lift platform 160 is recessed beneath the floor 116and the gates 150 are opened, the lift platform 160 is automaticallyraised to be level with the floor 116, unless a person or object is inthe path of the light gate sensors 164.

As an overview, the system 100 operates as follows. A patient ispreferably loaded onto the patient support apparatus 110 in a stagingarea. The patient is then transported through the front 154 andpositioned on the platform 160. While on the platform 160, the patientsupport apparatus is positioned with its longitudinal axis 168 alignedwith the x-axis. The patient support apparatus 110 may then be raised toa suitable height such that it clears the lower magnet pole 112. Thepatient support apparatus 110 is then moved over the magnet pole 112into the patient receiving space or gap 128. Once properly positionedover the pole 112, the apparatus 110 is then lowered to engage therotatable frame 136 at ledges 140. With the patient support apparatus110 mounted onto the frame 136, safety rails 170 and legs 174 are thenremoved from the patient support apparatus. The patient may then berotated and translated as discussed above so that the portion of thepatient's anatomy to be scanned is located in the magnet's isocenter.

In addition to performing scanning, the system 100 also provides aversatile and open enough environment that can also accommodate one ormore medical personnel O in addition to the patient. For example, thesystem may be used in performing a biopsy or other medical procedure. Inparticular, the space around the poles provides an unobstructed view ofa patient supported on the bed 142 in the gap 128. An attendant ormedical personnel may have 360° access to the patient from alllocations. In addition, the platform 160 may be adjusted so as toaccommodate the height of a doctor standing on the platform, who may beperforming medical procedures using the images provided by a scan topinpoint the location of tumors, tissue, bones or organs. In thatregard, the system may also include a display (not shown) that isattached to the upper magnet pole so that a surgeon could view images inreal time. The magnet design therefore provides an environment that canfunction as an operating room.

As best seen in FIG. 1, in a preferred embodiment, an antenna 316 isattached to the support apparatus 110 along an edge of a frame 138. Inaddition, the patient is shown as lying on a side such that the antennacan be placed adjacent to a portion of the patient's anatomy. As shown,the antenna is placed next to the patient's posterior surface, althoughthe patient and antenna may be maneuvered so that the antenna isadjacent to other anatomical areas of interest. In accordance with anaspect of the present invention, the antenna comprises a skeletalstructure (e.g., see FIGS. 3 and 7) that allows a surgeon access to thepatient's anatomy while the antenna receives resonance signals from theanatomical area of interest. This advantageously allows the surgeon, forexample, to view real time MR images of the patient's anatomy on aconveniently placed display while conducting a medical procedure. Suchprocedures may include actual surgery or biopsies. The real time MRimages desirably enhance the medical procedure by providing real timeviews of the surgical site during the procedure.

Alternatively, the system may be used to scan patients on an ambulatoryor outpatient basis. In that regard, the system allows two or morepatient support apparatus to be located in a staging area and used toload patients. When located in the staging area, the legs and wheels ofthe patient support apparatus are attached to the frame apparatus. Inthis mode, the patient apparatus is not docked to the lower pole, but isinstead used to support and transport the patient to the front of theroom housing the magnet. The patients may then be sequentially routedthrough the magnet thereby improving the throughput of the system 100.

With the bed 142 mounted to the frame 138, the legs 174 (see FIG. 1) maythen be preferably removed. In the preferred embodiment, the legs areremoved by grasping bar 143 and rotating it downwards 900 and towardsthe magnet pole. A lever (not shown) is then preferably used to releasethe legs 174 from the frame 138. FIG. 2 shows the bed 142 after it ismounted to the pole 130 and the legs have been removed. The legs mayinclude sensors that detect the presence of a load on the legs andprevent the legs from being removed from the bed frame.

As illustrated in FIG. 2, once the bed is mounted onto the pole 130, ormore particularly to rotation frame 136 at ledge 140, it may then berotated around the pole as is depicted by arrow A. As an additionalsafety feature, the rotation frame 136 is equipped with one or morestops 180 that allow the bed 142 to be docked at 0° of rotation as shownin FIG. 2, or 900 of rotation (line 182) on the stop 180 shown. Note,however, that the bed 142 may rotate 180° or 360° about the polar axis.In addition to rotation about the pole 130, the bed 142 may slideside-to-side along direction 186 on beams 194, which preferablytelescope along direction 186. The bed 142 may also cantilever on itsframe 138 along the direction 196. These additional adjustments allowfor greater flexibility with respect to bringing a patient close to adoctor, who is standing at the edge of the pole.

Turning now to FIG. 3 there is shown a partial perspective view of asystem for performing magnetic resonance imaging assisted surgery. Thesystem comprises a bed 310, an antenna support assembly 314 and anantenna 316. The bed 310 includes a frame 320 and a slab 324 mounted tothe frame 320. As shown, the bed 310 is mounted to the lower pole 130via the frame 320 and is operable to rotate, slide and cantilever asdiscussed above. The slab 324 includes a pair of longitudinal edges 328that are spaced apart to define a support surface 330 for a patient. Thelongitudinal edges 328 are L-shaped in cross-section (see A) and extendslightly above and over frames 320. In this way, the longitudinal edges328 allow a base member 332 (see FIG. 4) to be slid over the edges 328as shown.

The base member 332 includes first and second bars 338 that extendparallel to each other and are held apart by a rectangular plate 340 towhich they are connected to. The bars 338 are curved towards their endsso they extend up and over the sides 341 of the slab 324. The ends ofbars 338 are curved to form hooks 342 that are adapted to engage thelongitudinal edges 328 of the slab 324. Support sections 346 arepositioned between respective ends of the bars and provide additionalconnection points for the bars 338.

Although the sections 346 are not curved in the preferred embodiment togrip the edges 328, they may be curved to hook over the edges 328 of theslab 324. The support sections 346 each include a portion 350 thatprojects upwardly when the base member 332 is attached to the bed 310.The projecting portions 350 are a position lock for support sections346. By depress a cam lever to hold it in place, either side holds. Byreleasing the cam lever the assembly may be slid longitudinally alongthe bed 310. The types of positional locks are equally well suited. Asbest seen in FIG. 4, the antenna support assembly 314 includes a pair ofsidewalls 402 that are connected together via a cross-sectional beam406. The beam 406 is shaped at its lower end to engage the rectangularportion 350 of the base member 332. The sidewalls include notches 408 atone end 410. The notches 408 are adapted to engage the frame 320 alongits edge proximate the pole 130 and hold the antenna support assembly inplace. In the preferred embodiment, the support assembly 314 includesopenings 414 towards its distal end 418.

At the distal end 418, openings 422, 424 are formed in each sidewall 402to receive an upper rod 426. The opening 422 extends completely throughthe second sidewall 4182, while the opening 424 preferably extends intobut not through first side wall 4181. A lower rod 432 is also arrangedparallel to the upper rod 426 through an opening 434 in second sidewall4182. The end of lower rod 432 is inserted into the first sidewall 418,as shown. The other ends of upper and lower rods 426, 432 are insertedinto upper and lower rectangular blocks 444, 448. The upper and lowerrectangular blocks 444, 448 are connected together by a rod 450 thatextends vertically when the antenna support assembly 314 is assembledand attached to the bed 310.

A rod 458 is connected to rod 450 via connecting block 460. Theconnecting block 460 preferably includes a locking mechanism (e.g., aknob) that when released allows the block 460 and rod 458 to rotatearound the rod 450 (see S). A U-shaped holder 462 is formed at the otherend of rod 458 and used to hold the antenna 316 in place. In a preferredembodiment the antenna 316 may be connected to holder 462 such that itcan be rotated about an axis 466 that runs between the short sections ofthe holder 462 as shown. Where rotation is employed a locking mechanismto hold the antenna in place during a surgical procedure will also benecessary.

In addition to the types of rotation discussed above, the rod 458 mayalso be allowed to rotate in the direction R as shown. This would allowthe antenna 316 to be rotated between the substantially verticallyposition shown in FIG. 4 to a position where the antenna 316 is orientedin a substantially horizontal position or any position therebetween.Allowing for the rotation R provides additional versatility to thesystem. In particular, in some surgical procedures a patient may berequired to lie on their side. In such a procedure the antenna 316 canbe oriented as shown, i.e., with its planar surfaces extend in asubstantially vertical direction. Where a patient is lying on theirstomach or back the antenna may then rotated along direction R andparallel to either their back (posterior surface) or stomach (anteriorsurface). As is discussed in further detail below, this allows foradditional flexibility during a surgical procedure.

Turning now to FIG. 5A, there is shown a plan view of the antenna 316with one side of the housing 504 removed to reveal the internalarrangement of the coils. In accordance with an aspect of the presentinvention, the housing 504 is formed to provide a skeletal structurethat is contoured to match the coil geometry. This results in thehousing 504 having openings 508 through which a surgeon, for example,may insert his or her hands during a surgical procedure. As shown inFIGS. 4 and 5, there is a main opening 508, located at the center of thehousing, a second pair of openings 5082 located on opposite sides ofopening 508, and a third pair of openings 5083 located next to each ofthe openings 5082. The openings also server to reduce the weight of theantenna 316.

As best seen in FIG. 5A, the housing includes two coils. One coil is aloop coil 524 with a coil vector 526 (see FIG. 4) that is perpendicularto the surface of the housing 504. The second coil 530 includes two runs530, and 5302 and includes a coil vector 536 that extends perpendicularto coil vector 526 along the surface of the housing 504, as is shown inFIG. 4. In that regard, the coils 524 and 530 comprise a quad planarcoil geometry. Note, however, where a quad planar geometry such as shownin FIG. 5 a is employed, rotation along direction R as discussed abovemay not be desirable as it could result in the coil vector 526 beingparallel to direction of the static magnet field, i.e., vertical. Theuse of the quad planar coil arrangement of FIG. 5 advantageously allowsfor a larger field of view and deeper penetration into the anatomicalarea of interest.

Referring to FIG. 5B a planar ring coil assembly can be seen. The planarring coil assembly 550 has a housing 552 which contains a ring coil witha coil vector perpendicular to the surface of the housing 552. The ringcoil assembly 550 is shown coupled to a U-Shaped holder 554 which isattached to rod 556. Release lever 558 enables the ring coil assembly550 to be positioned and then locked into position. The ring coilassembly 550 may be used alternatively to antenna 316 shown in FIG. 4.

FIG. 5C shows a housing of a double-planar shoulder coil assembly. Thedouble-planar shoulder coil assembly 560 has a housing 562 whichcontains dual coils. The double-planar shoulder coil assembly 550 isshown coupled to a U-Shaped holder 554 which is attached to rod 556.Release lever 558 enables the double-planar shoulder coil assembly 550to be positioned and then locked into position. The double-planarshoulder assembly 560 may be used alternatively to antenna 316 shown inFIG. 4.

Although the present invention is well suited for use with a planar quadcoil and is so described herein, it is equally well suited for use witha planar ring coil and shoulder coil assembly such as a double-planarshoulder coil which are shown as well as with a other MRI coils such asa head coil, spine coil, knee/extremity coil, wrist coil, PlanarThoracic-Lumbar Coil, Quadrature Thoracic-Lumbar Coil, etc.

More particularly, where the coil is oriented as shown in FIG. 3, apatient may lay on their side with coil brought adjacent to theirposterior surface, e.g., back. Imaging may then be performed. As thehousing includes the openings 508, a surgeon may perform a surgicalprocedure on the patient's back with the antenna in place. This allowsthe acquisition of real time images which the doctor may use to locatethe surgical site via visual feedback provided by a monitor showing theimages. This would allow truly MRI assisted surgery. The placement of aquad planar coil adjacent to patient's anatomy also allows images to beobtained at a greater depth.

Turning now to FIG. 6A, there is shown an antenna support assembly 600in accordance with an additional aspect of the present invention. Thesupport assembly 600 may be used in lieu of the assembly 314 discussedabove.

The assembly 600 includes a bed locking sub-assembly 604 and coillocking sub-assembly 608. The bed locking sub-assembly 604 includes abase section 610. The base 610 includes end pieces 616 that are affixedto each end. End pieces 616 attaches or locks onto the bed 314 along thelongitudinal edges (see FIGS. 7A and 7B) and a rod 612 connectedperpendicularly to the base 610. As best seen in the exploded view ofFIG. 6B, the end pieces are preferably affixed to the ends of the baseusing one or more screws 618, although other methods of connecting theends thereto are also possible. Each end piece includes a locking leversection 622 that is rotatably mounted to the end piece using a spacer624. The end piece 616 is shaped so as to include a notch or hooksection 626. The hook section 626 is adapted to engage the L shapedsection A (see FIGS. 3 and 7) of the bed slab and locked into placeusing the locking levers 622.

More particularly, with reference to FIGS. 6B and 7A or 7B, the lockinglevers 622 each include a protruding portion 630. When the levers 622are rotated upward away from the base section 610, the bed lockingassembly 604 may be attached to a longitudinal edge of the slab. Oncethe hook section 626 is arranged to fit over the edge, the levers arerotated downward toward the base section 610 and the longitudinal edgeto which it is attached so that assembly 600 is secured to the bed. Whensecured, the assembly is oriented as shown in FIG. 7. That is, the basesection extends along the edge and such that the rod is oriented in avertical direction, while coil locking subassembly 608 is oriented in ahorizontal direction.

The coil locking sub-assembly 608 is attached to the lockingsub-assembly 604 via rod 612. As shown, the rod 612 includes a pluralityof openings 640 arranged in a line along its lengthwise direction. Theseopenings 640 are engaged by the knob and pin locking assembly 642. Asbest seen in FIG. 6B, the locking assembly 642 is inserted through anopening in connection block 644. This locking mechanism 642 allows theposition of the connection block 644 to be adjusted along the length ofrod 612. When the antenna support assembly is mounted to the bed, thisadjustment results in a height adjustment of the coil lockingsubassembly 608, as is shown in shadow 646 and may be better appreciatedfrom FIG. 7.

The connection block 644 also includes a second locking assembly 650that allows the coil locking subassembly 608 to be adjustedperpendicular to the direction of the rod 612. As best seen in FIG. 6B,the connection block 644 includes an upper section 644 ₁ and a lowersection 644 ₂. Both sections include a semicircular cut-out 648 asshown. A member 652 is positioned between the upper and lower sections644. The member 652 includes an opening 654 through which a screw 650 ₂is inserted. The screw 650 ₂ extends into the knob 650 ₁ and togetherthey form the second locking assembly along with the member 652. As canbe appreciated, by adjusting the knob 650 ₁, the upper section 644 andmember 652 move to allow rod 660 to slid within opening formed bysemicircular cut-outs 648. By tightening the knob 650 ₁, the rod 660 canbe held in place.

The coil locking sub-assembly 608 includes the rod 660 and a holder 670.As best seen in FIG. 6C, the rod 660 is attached to the holder 670 by apair of screws 672. The holder 670 includes a substantially U-shapedinner side wall 679 having a pair of holes 682 aligned along an axis684. A cylindrical member 688 is inserted within the holes 682 as shown.The cylindrical member 688 includes a hole running aligned along itsaxial direction. At one end, a rod 690 is inserted in the hole. In anassembled condition, the rod 690 protrudes from the hole and is insertedthrough opening 682. The rod 690 serves as a connection point to a lever692. The lever 692 allows the cylindrical member 688 to be locked inplace or released. With the lever 692 in the unlocked position, thecylindrical member 688 is allowed to slide parallel to axis 684 so thatan antenna, such as antenna 316, may be positioned within the holder 670(see FIG. 7). After the antenna is positioned in the holder the member688 is then slid through hole 682 ₁, holes in the antenna, and hole 682₂ and locked into place using lever 692.

The assembly 600 may be used in a surgical procedure as described aboveand may be fitted with the quad planar antenna 316 as shown in FIG. 7.In the preferred embodiment the base is approximately 12 inches long andthe rod 612 extends approximately 15 inches away from the base 610. Therod 660 of the coil locking assembly 608 is preferably approximately 15inches long and the distance from the from the end of the lever 692 tothe other end of the holder 670 is approximately 11 inches.

Referring to FIG. 8 shows a cross section detail of the bed extrusion.End pieces 616 are affixed to each end the base 610 (not shown in thisfigure). The end pieces 616 attaches or locks onto the bed 314 along thelongitudinal edge 1002 (shown in FIGS. 7A and 7B as well). Each endpiece 616 includes a locking lever section 622 that is rotatably mountedto the end piece using a spacer. The end piece 616 is shaped so as toinclude a notch or hook section 626. The hook section 626 is adapted toengage the L shaped section A 1002 of the bed slab and locked into placeusing the locking levers 622.

The support assembly 600 is simpler in design than assembly 314,includes less parts and attaches to bed without the aid of the basemember 332.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A method for performing a surgical procedure, comprising: positioning a patient on bed in a receiving space of a magnetic resonance imaging magnet; positioning an antenna coil assembly adjacent to a portion of the patient's anatomy; acquiring a magnetic resonance image of the patient's anatomy adjacent the antenna coil assembly; performing a surgical procedure on the patient's anatomy adjacent the antenna coil assembly; and repetitively acquiring images of the patient's anatomy adjacent the antenna coil assembly as the surgical procedure is performed.
 2. The method as recited in claim 1 further comprising the step of aligning the antenna coil to the portion of the patient's anatomy.
 3. The method as recited in claim 1 further comprising positioning the antenna coil assembly adjacent to the patient's anterior surface.
 4. The method as recited in claim 1 further comprising positioning the antenna coil assembly adjacent to the patient's posterior surface.
 5. The method as recited in claim 1 further comprising positioning the antenna coil assembly adjacent to the patient's side surface. 